Work in progress! Please don't translate it, yet. But feel free to correct spelling mistakes ;)
Our geometry kernel (OCCT) includes a command line application called DRAWEXE. It allows to use the geometry kernel from an interactive prompt. It can be scripted using the tool command language (tcl). It is used at OpenCASCADE for automatated intergration testing.
A lot of problems in FreeCAD are caused by our geometry kernel. In order to attribute those problems, they need to be reproduced outside of FreeCAD. The motivation for the exporter is to export a sub-tree of a FreeCAD document as a script for the DRAWEXE command. This subtree can then be recreated using the "source" command of DRAWEXE.
Every object derived from Part::Feature which is not (yet) supported will be exported as a BREP shape